A great deal of design effort has been devoted over the years to the subject of hand-pulled golf carts, most of such effort being directed toward the development of various folding mechanism and and concepts to permit the cart to be stowed in a minimum of space after use.
Many of the resulting designs represent a compromise between strength and stability in the erected condition and lightness and compactness in the folded condition; i.e., those carts which provide a substantial wheel base for stability when erected are not only fairly large when folded, but also require a large number of components which add weight and structural complexity. One such device utilizes non-removable wheels which are connected to left and right parallelogram strut assemblies which are automatically extended when a pivotal handle is rotated from a folded position to the extended position. In this device, extension of the wheel struts and wheels also raises the wheels relative to the bottom of the main support member thereby to create the three-point support arrangement which is necessary to create stability when the cart and bag stand on the ground. See Abgarian U.S. Pat. No. 3,079,166.
Other prior art golf carts are shown in Carr et al U.S. Pat. No. 2,414,017, Marvin U.S. Pat. No. 2,518,803, Burtt U.S. Pat. No. 2,508,059, Strain U.S. Pat. No. 2,399,518, Chamberlin et al U.S. Pat. No. 2,335,579, Widegren U.S. Pat. No. 3,985,373, Vanden Hoek U.S. Pat. No. 2,572,408, Morehouse U.S. Pat. No. 2,415,392, and Albertson U.S. Pat. No. 4,302,029. Carr and Marvin, as examples, use tripod arrangements with wheel base struts and diagonal braces which slide on a main support member. Neither Carr nor Marvin discloses actual half-axle wheel supports, both appear to contemplate fixed wheels and both show the plane of the wheels spaced from the bottom of the main support member and the use of the main support member as part of the tripod support system.
The present invention provides a highly compact, lightweight and mechanically simple foldable cart for golf bags and the like which provides adequate wheel base for stability when erected, yet which is lightweight and extremely compact when folded.
In general, I achieved the objectives of my invention through a structure which includes a main support member, which may be tubular in configuration, fold-out bag bottom support and handle members which are pivotally connected to the main support member at the opposite ends thereof in mirror image fashion, a pair of half-axles which are pivotally connected to the main support member at or near the bottom, a sliding anchor member which is mounted on the main support member and which is slidable between two spaced anchor points, and a pair of axle support struts which are pivotally connected between the anchor member and midpoints along the half-axles to fold and extend the half-axles as the anchor member is moved between the fixed position points. The strut members are preferably hollow and box-like in section and are slotted along at least a substantial portion thereof to receive therein the outboard portions of the half-axles when folded; i.e., the portions of the half-axles which lie outboard of the pivotal connection between the half axles and the struts nest into the support struts such that the overall length of the half-axles and the support struts, when folded, is somewhat less than the length of the main support member. In this fashion I achieve an extremely lightweight and compact, yet strong and stable, foldable cart which is particularly useful on the golf course. My invention may, of course, be used for purposes other than the transportation of golf bags but is useful for this specific and popular purpose.
In the preferred embodiment of my invention, hereinafter described in detail, I utilize removable snap-on wheels thereby to eliminate the need for complex parallelogram mechanisms to maintain the wheels in a specific attitude relative to the main support tube as they are folded. The acts of removing and installing the wheels add minimal complexity and inconvenience to the utilization of my device add substantially to the compactness thereof as will be hereinafter explained.
I also prefer in the specific and illustrative embodiment hereinafter described, to utilize a bag support mechanism which is configured to provide, along with the wheels, a stable three-point support arrangement and which is slotted so as to permit the bottom bag support member to fold into close adjacent, if not contacting, relationship with the main support member.